Here it is, and it would still be considered a fine system by today's standards.
Harman Kardon A300
Specifications -
Power output: 12 watts per channel into 8Ω (stereo)
Frequency response: 15Hz to 70kHz
Total harmonic distortion: 1%
Input sensitivity: 3mV (MM), 125mV (line)
Signal to noise ratio: 60dB (MM), 75dB (line)
Speaker load impedance: 8Ω to 16Ω
Tube complement: 4 x 7408, 4 x 12AX7, 1 x 12AU7
Dimensions: 15-1/4 x 5-7/16 x 11-1/2 inches
Weight: 25lbs
Finish: brushed gold front panel
I built my amp/preamp from a HK kit in my senior year of high school, which was great fun. I took great pains to route all of the wires neatly and make perfect solder joints. It sounded phenomenal & performed like a champ for almost 40 years, before developing some problems. I'd love to get it up and running again.
That power button glowed purple, unlike anything else out there. Always dug that subtle feature.
I also built a Rek-O-Kut K34H belt drive turntable (kit), and mounted a Grado Laboratory Series arm & cartridge as part of my original sound system with the HK amp. My speakers were a pair of AES Gigolo bookshelf units (kit), infinite baffles with 8" full range speakers. This was all circa 1961. Kid on a mission with a very modest budget.

Rek-O-Kut Turntable (not mine + incorrect arm)

Grado Laboratory Series Arm & Cartridge
What was your first sound system?